Striking a heavy blow to the JDS in its heartland, the ruling Congress in Karnataka on Saturday wrested the Mandya and Bangalore Rural Lok Sabha seats from it with impressive margins in the fiercely fought bypolls.

Multi-lingual actress Ramya on her electoral debut defeated C S Puttaraju of JDS in Mandya, the nucleus of his party's Vokkaliga vote base, by a margin of 67,611 votes, officials said.

In Bangalore Rural, it was a spectacular victory for Congress and heartbreaking defeat for JDS as former Chief Minister H D Kumaraswamy's wife Anitha Kumaraswamy lost by a huge margin of over 1.37 lakh votes to ruling party's D K Suresh, brother of state party leader D.K.Shivakumar.

Kumaraswamy, son of former Prime Minister H D Deve Gowda, had held the Bangalore Rural seat before he gave it up after winning the May Assembly polls and the Gowda family had invested all its prestige into the battle. He had won the seat by over 1.3 lakh votes in the 2009 Lok Sabha elections.

JDS had struck an understanding with the BJP which did not field candidates in both the constituencies where it wields no significant electoral influence.

The poll outcome comes to the Congress just days after it celebrated 100 days in office still euphoric over its spectacular victory in the May Assembly polls that catapulted it to power with absolute majority, unseating BJP.

For Chief Minister Siddaramaiah, the result has come as a big boost to consolidate his position as an adverse outcome would have given a handle to a section of his own partymen not happy with his style of functioning.

The August 21 bypoll had also almost turned into an arena for scoring personal points for both Siddaramaiah and Kumaraswamy who made no-holds-barred attack against each other.

Siddaramaiah said JDS had been taught a lesson by voters who also saw through the JDS' alliance with BJP and KJP of former Chief Minister B S Yeddyurappa.

In an immediate fallout, Kumaraswamy met Deve Gowda and conveyed his decision to step down as state unit chief and as opposition leader in the Assembly. "I underwent a cardiac surgery and maybe, the voters thought I need rest," he was quoted as saying emotionally by a party release.

Both Ramya and Suresh maintained convincing leads right from the beginning as the counting of votes for the by-polls was taken up this morning and gradually increased the lead to unassailable levels.

The by-poll to Mandya was necessitated following the resignation of N Cheluvarayaswamy after he became MLA.

In the May Assembly polls, JDS had won five of the eight seats in Mandya district.

In Bangalore Rural, Congress had secured the support of Samajwadi Party MLA, C P Yogeeshwara, who had defeated Anita Kumaraswamy in the May polls.

TDP wins bypoll in Andhra Pradesh

Telugu Desam Party (TDP) on Saturday comfortably won the by-election from Avanigadda Assembly seat in Krishna district of Andhra Pradesh.

The main Opposition party's Ambati Srihari Prasad defeated his nearest rival Saikam Rajasekhar, an Independent, by a huge margin of 61,644 votes.

Prasad secured 75,282 votes while Rajasekhar got 13,638 at the end of counting, sources in the Election Commission said.

The other Independent in the fray, Ravi Subrahmanyam, received 3,389 votes out of the total 92,309 ballots cast in the August 21 polling, for which major political parties had not fielded their candidates.

The by-election was necessitated due to the death of sitting Avanigadda MLA Ambati Brahmanaiah of TDP in April. Prasad is Brahmanaiah's son.

On TDP's request, main political parties, including ruling Congress and Jaganmohan Reddy-led YSR Congress, did not field their candidates to make it an unanimous election.

But the two Independents refused to withdraw from the fray making voting inevitable.